diff --git a/src/Symfony/Bundle/FrameworkBundle/Routing/Router.php b/src/Symfony/Bundle/FrameworkBundle/Routing/Router.php
index 98d362469a46..aa9877ae6e67 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Routing/Router.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Routing/Router.php
@@ -71,8 +71,13 @@ private function applyParameters(RouteCollection $collection)
                 $this->applyParameters($route);
             } else {
                 foreach ($route->getDefaults() as $name => $value) {
-                    if (preg_match('#^%(.+)%$#', $value, $matches) && $this->container->hasParameter($matches[1])) {
-                        $route->setDefault($name, $this->container->getParameter($matches[1]));
+                    if (!$value || '%' !== $value[0] || '%' !== substr($value, -1)) {
+                        continue;
+                    }
+
+                    $key = substr($value, 1, -1);
+                    if ($this->container->hasParameter($key)) {
+                        $route->setDefault($name, $this->container->getParameter($key));
                     }
                 }
             }
diff --git a/src/Symfony/Bundle/FrameworkBundle/Tests/Routing/RouterTest.php b/src/Symfony/Bundle/FrameworkBundle/Tests/Routing/RouterTest.php
new file mode 100644
index 000000000000..5d1558272ec3
--- /dev/null
+++ b/src/Symfony/Bundle/FrameworkBundle/Tests/Routing/RouterTest.php
@@ -0,0 +1,83 @@
+<?php
+
+/*
+ * This file is part of the Symfony framework.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * This source file is subject to the MIT license that is bundled
+ * with this source code in the file LICENSE.
+ */
+
+namespace Symfony\Bundle\FrameworkBundle\Tests\Routing;
+
+use Symfony\Bundle\FrameworkBundle\Routing\Router;
+use Symfony\Component\Routing\Route;
+use Symfony\Component\Routing\RouteCollection;
+
+class RoutingTest extends \PHPUnit_Framework_TestCase
+{
+    public function testPlaceholders()
+    {
+        $routes = new RouteCollection();
+        $routes->add('foo', new Route('/foo', array(
+            'foo'    => '%foo%',
+            'bar'    => '%bar%',
+            'foobar' => 'foobar',
+            'foo1'   => '%foo',
+            'foo2'   => 'foo%',
+            'foo3'   => 'f%o%o',
+        )));
+
+        $sc = $this->getServiceContainer($routes);
+        $sc
+            ->expects($this->at(1))
+            ->method('hasParameter')
+            ->will($this->returnValue(false))
+        ;
+        $sc
+            ->expects($this->at(2))
+            ->method('hasParameter')
+            ->will($this->returnValue(true))
+        ;
+        $sc
+            ->expects($this->at(3))
+            ->method('getParameter')
+            ->will($this->returnValue('bar'))
+        ;
+
+        $router = new Router($sc, 'foo');
+        $route = $router->getRouteCollection()->get('foo');
+
+        $this->assertEquals('%foo%', $route->getDefault('foo'));
+        $this->assertEquals('bar', $route->getDefault('bar'));
+        $this->assertEquals('foobar', $route->getDefault('foobar'));
+        $this->assertEquals('%foo', $route->getDefault('foo1'));
+        $this->assertEquals('foo%', $route->getDefault('foo2'));
+        $this->assertEquals('f%o%o', $route->getDefault('foo3'));
+    }
+
+    private function getServiceContainer(RouteCollection $routes)
+    {
+        $sc = $this->getMock('Symfony\Component\DependencyInjection\ContainerInterface');
+        $sc
+            ->expects($this->once())
+            ->method('get')
+            ->will($this->returnValue($this->getLoader($routes)))
+        ;
+
+        return $sc;
+    }
+
+    private function getLoader(RouteCollection $routes)
+    {
+        $loader = $this->getMock('Symfony\Component\Config\Loader\LoaderInterface');
+        $loader
+            ->expects($this->any())
+            ->method('load')
+            ->will($this->returnValue($routes))
+        ;
+
+        return $loader;
+    }
+}